[PATCH 1/3] touchscreen: sun4i-ts: A10 (sun4i) has a different temperature curve

[Dmitry Torokhov]

On Sun, Mar 08, 2015 at 09:53:40PM +0100, Hans de Goede wrote:
> Testing has revealed that the temperature in the rtp controller of the A10
> (sun4i) SoC has a different curve then on the A13 (sun5i) and later models.
> 
> Add a new sun5i-a13-ts compatible to differentiate the newer models and
> set the curve based on the compatible string.
> 
> The new curve is still not ideal on all A10-s, that seems to have to
> do with there being a large spread between different A10-s out there,
> the new curve us based on callibration results on 4 completely different
> models:
>                         raw min raw max temp min temp max stepsize offset
> Tong Zhang's hackberry    2402    2680    45.0     80.0    0.125   -255.3
> Hansg's Cubieboard        2207    2300    36.0     45.0    0.096   -175.8
> Olliver's lime 1 (*):     2258    2537    48.3     87.1    0.139   -265.7
> Olliver's lime 2 (*):     2222    2486    46.7     91.7    0.170   -331.0
> *) from: http://linux-sunxi.org/Temperature_Calibration
> 
> Average all 4:                                             0.133   -257.0
> Average without outliers (middle 2):                       0.132   -261.0
> 
> Since it is better to slightly overreport the temperature this patch uses
> the average of all 4 as curve.
> 
> This fixes the temperature reported on the A10 being much higher then
> expected.
> 
> Cc: Tong Zhang <lovewilliam at gmail.com>
> Cc: Olliver Schinagl <o.schinagl at ultimaker.com>
> Reported-by: Tong Zhang <lovewilliam at gmail.com>
> Signed-off-by: Hans de Goede <hdegoede at redhat.com>


Applied, thank you.

> ---
>  .../devicetree/bindings/input/touchscreen/sun4i.txt      |  3 ++-
>  drivers/input/touchscreen/sun4i-ts.c                     | 16 +++++++++++++---
>  2 files changed, 15 insertions(+), 4 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt b/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt
> index 433332d..d59d252 100644
> --- a/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt
> +++ b/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt
> @@ -2,7 +2,8 @@ sun4i resistive touchscreen controller
>  --------------------------------------
>  
>  Required properties:
> - - compatible: "allwinner,sun4i-a10-ts" or "allwinner,sun6i-a31-ts"
> + - compatible: "allwinner,sun4i-a10-ts", "allwinner,sun5i-a13-ts" or
> +   "allwinner,sun6i-a31-ts"
>   - reg: mmio address range of the chip
>   - interrupts: interrupt to which the chip is connected
>   - #thermal-sensor-cells: shall be 0
> diff --git a/drivers/input/touchscreen/sun4i-ts.c b/drivers/input/touchscreen/sun4i-ts.c
> index b93a28b..66ccd5a 100644
> --- a/drivers/input/touchscreen/sun4i-ts.c
> +++ b/drivers/input/touchscreen/sun4i-ts.c
> @@ -258,6 +258,15 @@ static int sun4i_ts_probe(struct platform_device *pdev)
>  		/* Allwinner SDK has temperature = -271 + (value / 6) (C) */
>  		ts->temp_offset = 1626;
>  		ts->temp_step = 167;
> +	} else if (of_device_is_compatible(np, "allwinner,sun4i-a10-ts")) {
> +		/*
> +		 * The A10 temperature sensor has quite a wide spread, these
> +		 * parameters are based on the averaging of the calibration
> +		 * results of 4 completely different boards, with a spread of
> +		 * temp_step from 96 - 170 and temp_offset from 1758 - 3310.
> +		 */
> +		ts->temp_offset = 2570;
> +		ts->temp_step = 133;
>  	} else {
>  		/*
>  		 * The user manuals do not contain the formula for calculating
> @@ -330,10 +339,10 @@ static int sun4i_ts_probe(struct platform_device *pdev)
>  	 * finally enable tp mode.
>  	 */
>  	reg = STYLUS_UP_DEBOUN(5) | STYLUS_UP_DEBOUN_EN(1);
> -	if (of_device_is_compatible(np, "allwinner,sun4i-a10-ts"))
> -		reg |= TP_MODE_EN(1);
> -	else
> +	if (of_device_is_compatible(np, "allwinner,sun6i-a31-ts"))
>  		reg |= SUN6I_TP_MODE_EN(1);
> +	else
> +		reg |= TP_MODE_EN(1);
>  	writel(reg, ts->base + TP_CTRL1);
>  
>  	/*
> @@ -383,6 +392,7 @@ static int sun4i_ts_remove(struct platform_device *pdev)
>  
>  static const struct of_device_id sun4i_ts_of_match[] = {
>  	{ .compatible = "allwinner,sun4i-a10-ts", },
> +	{ .compatible = "allwinner,sun5i-a13-ts", },
>  	{ .compatible = "allwinner,sun6i-a31-ts", },
>  	{ /* sentinel */ }
>  };
> -- 
> 2.3.1
> 

-- 
Dmitry